Duet3 expansion - power supply

dutti

hey communitiy,
Do I have to connect the expansion board power via the mainboard or should I connect it directly to the RSU?
maybe a stupid question.....but I´m scared todestroy the electronic.
KR Richard Gruna
tahnks

Phaedrux

Do you mean daisy chaining the power from the main board to the expansion? Connecting directly to the power supply would probably be best. I don't think it has the same shared ground connection that the Duet2 and Duex board has.

dc42

You can connect the expansion board directly to the PSU, or daisy chain the power from one board to another. There is just one combination that I have found not to work well:

High powered bed heater driven directly from the Duet 3 bed heater output
Long and not very thick wires between the PSU and the Duet 3 main board
Expansion board powered directly from the PSU

This combination generates enough differential ground noise to upset the CAN bus signals. So if using the Duet 3 to drive a high-powered heater directly, position the PSU close to the Duet 3 and use short thick power wires between them.

dutti

@Phaedrux
I use Duet3 6hc with the duet3 expansion 3hc...
I´ll try to connect both boards directly to the RSU.

@dc42 To avoid this problems I´ll use a SSR to heat the bed. In this case its not direct driven by the Duet3, rigth?

Phaedrux

@barbarossa-cologne said in Duet3 expansion - power supply:

In this case its not direct driven by the Duet3, rigth?

Correct.